AP performance (again): txpower regulation

[Lev Serebryakov]

Hello, Adrian.
You wrote 9 сентября 2011 г., 12:02:46:


> Try forcing the TX/RX antenna then. Look at the output of athstats -
> see how rx antenna isn't balanced?
> I bet half your problem is that half your packets are going in/out of
> a disconnected antenna.
> Antenna profile:
> [1] tx  8543738 rx  4922481
> [2] tx   544837 rx    14216

> See? :)

> Try sysctl dev.ath.0.diversity=0
> sysctl dev.ath.0.txantenna=1
> sysctl dev.ath.0.rxantenna=1

> See if that improves things. If not, try antennas = 2.
  No luck. I've attached second antenna (exactly the same long
 rubberduck 9-10dB model, I have two of them at hands). Result is the
 same: "formal" speed is 54M often, but speed is only 4-5Mbit today
(yesterday it was 10Mbit!), I've tried both antennas by one
(diversity=0, [tx|rx]antennas=[1|2]), results are exactly the same.
Yes, athstats shows, that these sysctls works (counters for disabled
antenna stop), but bandwidth is the same. Here is output of athstats
after almost hour of "iperf", mostly with both antennas turned on
(before experiments with diversity it was only 2400 rx frames on
second antenna and about 200K vs 1M tx frames 1st vs 2nd antennas).

gateway# ./athstats9
958888   data frames received
1583913  data frames transmit
55853    tx frames with an alternate rate
988328   long on-chip tx retries
20281    tx failed 'cuz too many retries
24M      current transmit rate
151      tx frames with no ack marked
1556918  tx frames with short preamble
18443    rx failed 'cuz of bad CRC
100      rx failed 'cuz of PHY err
    4        OFDM restart
    96       CCK restart
32683    beacons transmitted
112      periodic calibrations
-0/+0    TDMA slot adjust (usecs, smoothed)
41       rssi of last ack
36       avg recv rssi
-95      rx noise floor
26844    tx frames through raw api
12       cabq frames transmitted
2        cabq xmit overflowed beacon interval
41       switched default/rx antenna
4        noise immunity level
2        spur immunity level
8        ANI increased noise immunity
6        ANI increased spur immunity
2        ANI decrease spur immunity
4        ANI enabled OFDM weak signal detect
4        ANI disabled CCK weak signal threshold
28509691 cumulative OFDM phy error count
291680   cumulative CCK phy error count
68       ANI forced listen time to zero
988311   missing ACK's
24474    bad FCS
11       average rssi (beacons only)
Antenna profile:
[1] tx  1188167 rx   942337
[2] tx   375448 rx    16551


-- 
// Black Lion AKA Lev Serebryakov <lev at serebryakov.spb.ru>